how much of a sound barrier is sheetrock ?

amakarevic

right now, i have a bare ceiling, i.e. exposed beams and hardwood from upstairs. i can hear my upstairs-living tenants whispering.

once i put a sheetrock ceiling, and perhaps some thermal insulation in between, will it get any better or should i plan for a separate layer of sound barrier ? like panels they use for music studios. they are about the size and thickness of drywall but was hoping to avoid it because that would mean a double layer on the ceiling, especially problematic with recessed lights etc.

thanks,

- a -

AtlanticWBConst.

Sheetrock thickness can decrease sound transmission:

Drywall provides a thermal resistance R-value of 0.32 for three-eighths-inch board, 0.45 for half inch, 0.56 for five-eighths inch and 0.83 for one-inch board. In addition to increased R-value, thicker drywall has a higher sound transmission class. - http://en.wikipedia.org/wiki/Sheetrock

Information on Sound Transmission Class Ratings: http://en.wikipedia.org/wiki/Sound_transmission_class

Resilient channel with multiple layers of 5/8" sheetrock or acoustic rated sheetrock is the most common method, accompanied by the use of acoustic sealant and acoustic insulation. There also other factors that can aid in transmitting sound, that should be looked at and corrected.

Discussions, information, and materials related to soundproofing:

http://www.soundproofing101.com/

http://www.soundproofing.org/

http://forum.ecoustics.com/bbs/messa...79/288346.html

http://www.acousticalsurfaces.com/ac...phone.htm?d=16

http://www.glacierbay.com/insulation_ultradb.asp

http://insulation.sitepoint.com.au/p...-QuietZone.pdf

http://www.constructionresources.com...e/acoustic.asp

http://www.acousticsfirst.com/vinyl.htm

http://en.wikipedia.org/wiki/Soundproofing

http://www.extremesoundproofing.com/...cs/basics.html

http://www.soundprooffoam.com/

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Termite

Resilient channel is a very cost-effective method of sound attenuation. RC is light guage metal strips that fasten to the joists, running perpindicular to them. The sheetrock is then installed with screws just long enough to catch the channel, but not the joist. This eliminates the direct contact with the framing, which is how a lot of sound gets transmitted. It is no tougher than hanging rock normally.

Thermal insulation batts will help, but won't do much on their own.

One BIG cautionary note...
If you're in a multifamily building, firewalls and floor-ceiling fire assemblies are probably/hopefully involved. Disturbing the existing ceiling membrane will of course compromise this assembly. I'd advocate pulling a permit, and would take the necessary measures to ensure that the system you're putting in is equivalent or better than what you're taking out. You don't want to compromise that floor system prematurely in a fire. There are many UL and Gypsum Ass'n assemblies that involve RC channel.

If you're renting a bedroom to someone in a single family house, this isn't such an issue.

HandyPete

Drywall is strange stuff. I'm not an expert but...

If the sound is coming from within the room (like a studio) drywall sucks, the hard surface simply reflects the sound back into the room. If the sound comes from outside, it's a bit different.

In both case the board acts like a loudspeaker cone and vibrates as a whole unit. Anything physical attached the board will transmit the sound waves also.

What you want is something dense, soft and absorbing. Geez..easy (not)

This is what I did..

1) The cavity beween the joist is filled with Roxul "Safe 'n Sound" it's like a fiberglass batt but is flame retardant and has small particles of Iron in it. The stuff is great. IMPORTANT: install it right! no voids! a nice clean install!

2) Install 4x8 sheets of 1/2" lightweight fiber sheathing.

3) over the sheathing screw your 1x3 furring strips.

4) Screw the RC channels to the strips

5) Apply a thin coat of special soundproofing caulking on the RC (the stuff remains soft and never dries)

6) Use 5/8" firecode sheetrock ..it's heavy but great stuff!

7) Don't butt sheets together or in corners! leave a 1/16" for sound.

8) Tape with Durabond 45

....ain't no more sound!

- pete

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---pete

TomBrooklyn

Don't use recessed lights if you want maximum sound attenuation. Or else you can box the back of the cans in a drywall box but that is considerably more work.

TomBrooklyn

From there website, it looks like this stuff is only available in Canada. http://www.roxul.com/sw10395.asp

AtlanticWBConst.

It is available in the US. We use it alot. Most building Supply houses stock it. I do believe that even the Big Home Improvement Stores carry it too.

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amakarevic

what is fiber sheathing ?

what are furring strips ?

seems complicated overall but thanks.

AtlanticWBConst.

By fiber sheathing, I believe he means: Sound Board
Example: http://www.gp.com/build/product.aspx?pid=1071

By furring strips, I believe he means using either steel Resilient Channel, or wood strips. Example: http://www.soundproofing.org/infopages/channel.htm

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jcalvin

Just turn down your hearing aide any you will be fine.

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Cal

You hired WHO?
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